The invention relates generally to ultra-long-haul optical networks and particularly to methods associated with restoring a circuit within an ultra-long haul optical network.
In some known systems, optical-electrical-optical (OEO) regeneration is used to amplify signals in long-haul links. Such OEO regeneration can be performed, for example, in cross-connects that define the nodes within a network. Restoration within such a network is typically performed at these cross-connects such that alternative paths can be defined on-the-fly from a pre-established pool of restoration capacity. Because the transmitted signals for each link between two adjacent nodes within a path each has a given wavelength, known network restoration techniques typically need not manage the wavelengths of transmitted signals along a restoration path.
All-optical networks (i.e., networks using optical regeneration without electrical conversion), however, typically need to manage the wavelength usage for the various links within a restoration path. In addition, unlike networks that use OEO regeneration, networks that use optical regeneration without electric conversion typically need to manage changes in the cross talk and the total-power-per-link resulting from the restoration path.
Thus, a need exists for methods of managing changes in an optical network to accommodate restoration path actuation and wavelength usage in an efficient and effective manner.